Question : Emails from exchange 2003

Hi
We have exchange 2003 and what ever emails we are sending to our head office is getting rejected,  I checked all configuration and everything is working fine.
Please find below the bounce back message
Your message did not reach some or all of the intended recipients.

      Subject:      Test email
      Sent:      4/17/2007 11:21 AM

The following recipient(s) could not be reached:

      [email protected]om on 4/17/2007 11:21 AM
            There was a SMTP communication problem with the recipient's email server.  Please contact your system administrator.
            #5.5.0 smtp;553 http://www.spamhaus.org/query/bl?ip=83.110.13.145>


If some one can please help me on this issue

thanks and regards
JInesh Kumar

Answer : Emails from exchange 2003

That is an identical error to before - so it still isnt working.

try a telnet test to that mail server (emirates) and see if it actually receives mail -> http://www.amset.info/exchange/telnet-test.asp

Alternatively, the easier way would be to call your ISP and ask why it is not working - they may require authentication